What Does the Primitive Atrium Become

The primitive atrium becomes the anterior portions of both the right and left atria, and the two auricles. The sinus venosus develops into the posterior portion of the right atrium, the SA node, and the coronary sinus.

What does primitive ventricle give rise to?

The primitive ventricle or embryonic ventricle of the developing heart, together with the bulbus cordis that lies in front of it, gives rise to the left and right ventricles. The primitive ventricle provides the trabeculated parts of the walls, and the bulbus cordis the smooth parts.

What forms the left atrium embryology?

In the embryo, there is initially a single pulmonary vein next to the posterior left of the septum primum. With the lung buds’ co-development, the pulmonary vein and its branches become a part of the left atrium.